Parashas Acharei Mos · Passuk 17:11
Chabad.org — English translation + Rashi
Torah Temima points to Kerisos 22a.
English: “By the soul it atones” — only blood with which the life-force departs effects kapparah; blood that does not carry the nefesh does not.
Dam hanefesh
Kapparah requires the lifeblood (dam hanefesh); residual or non-lifeblood is insufficient for atonement.